Researchers from the "Consejo Superior de Investigaciones Científicas" (CSIC) have found a synthetic derivative of morphine which, when administered in rats, shows an analgesic effect one hundred times more powerful and twice as durable than morphine, as well as having fewer side effects.

The finding, published in the Journal of Medicinal Chemistry, opens the door to design new and better analgesics for the treatment of chronic and severe pain.

"Although in the past 40 years many new compounds with analgesic capacity have been discovered, there has been no significant progress for the treatment of chronic pain," says researcher Gregory Valencia. "This is the first time that a sugar (mannoside) derivative of morphine shows more analgesic capacity than the original drug".